Green MP Chlöe Swarbrick hit back at an interjecting National MP during a speech on climate change - calling out, "OK, boomer", in the House.
The second reading of the Climate Change Response (Zero Carbon) Amendment Bill passed last night with the support of all parties except ACT.
During the speeches from MPs, Ms Swarbrick told Parliament, "We are in a climate crisis, if we don't get this right, nothing else matters".
"How many world leaders for how many decades have seen and known what is coming but have decided that it is more politically expedient to keep it behind closed doors?" Ms Swarbrick asked Parliament yesterday.
"My generation and the generations after me do not have that luxury. In the year 2050 I will be 56 years old, yet right now, the average age of this 52nd Parliament is 49 years old."
National MP Todd Muller interjected saying, "That's impossible".
"OK, boomer," Ms Swarbrick shot back.
"OK Boomer" is a phrase popular on the internet to mock members of the Baby Boomer generation (born between 1946 and 1964), particularly in response to criticism of younger people.
Amusingly, the caption service on the Parliament TV misinterpreted Ms Swarbrick's comments as "OK Berma".
The Climate Change Response (Zero Carbon) Amendment Bill sets out a 10 per cent reduction target for biological methane emissions by 2030, and "aims" for a 24-47 per cent reduction by 2050.
It proposes limiting global warming no more than 1.5 degrees Celsius.